Flat panel displays have always been one of the displays that people are continuously pursuing to develop, and field emission display is one of them. In the 1960s, Ken Shoulder proposed the idea based on field emission cathode arrays (FEAs) cathode ray micro devices, thus the researches of using FEAs to design and to prepare flat panel displays and light source devices have received great attentions. The working principle of the new type field emission devices is similar to that of the traditional cathode ray tube (CRT), the application of imaging or lighting are realized by bombardment of electron beam to trichromatic fluorescence powders of red, green and blue. The field emission devices have potential advantages in the aspects such as brightness, viewing angle, response time, range of operating temperature and energy consumption.
One of the key factors of the preparation of field emission devices with excellent properties is the preparation of luminous material with excellent properties, and that is the preparation of fluorescence powders. Currently, the fluorescence materials used in field emission devices mainly are the fluorescence powders of series sulfide, series oxide and series oxysulfide used in traditional cathode ray tube and projection television tubes. The fluorescence powders of series sulfide and series oxide have high brightness and certain electrical conductivity, while, these fluorescence powders are prone to be decomposed under the bombardment of large electron beam, could produce sulfur to poison the cathode tip, and could generate other sediment covering the fluorescence powders surface, thus reducing the luminescence efficiency of the fluorescence powders and decreasing the lifetime of the field emission devices. The fluorescence powders of series oxide have good stability, while their luminescence efficiency are not high enough, and they are generally made from insulators materials. The borate luminous material of series sulfide, series oxide and series oxysulfide can not meet needs of the above properties, and the properties of these series are to be improved and enhanced.